Apparatus for conserving pressure used in air locks



April 193%. w. B. UPDEGRAFF' APPARATUS FOR CONSERVING PRESSURE ussn IN AIR LOCKS Filed June' 5,1957

2. Sheets-Sheet l ATTORNEYS April 12, 1938.

w. B. UPDEGRAFF APPARATUS FOR CONSERVINCT PRESSURE USED IN AIR LOCKS Filgd June 5, 1957 Z SheetS-Sheet 2 @Mw-M ATTORNEYS Patented Apr. 12,1938

PATENT OFFICE APPARATUS FOR CONSERVING PRESSURE f I USED IN R LocKs William B. Updegraff, Elizabeth, N. J. Application June 5, 1937, Serial'No. 146,643

8 Claims.

1 This invention relates to apparatus for conserving pressure used in air locksin connection with operations conducted under pressure, such as the building of tunnels, sinking of deep foundations, or other works where air pressure is necessary to prevent the entrance of water into the working chamber. In all such works it is necessary to provide air locks through which men and material are passed into or out of the working chamber -Wheneveranythin'gis passed out of the working chamber through the air lock, it has heretofore been necessary to reduce or relieve the pressure in the lock by venting it to an atmosphere of lower pressure, and the energy of the compressed air in the lock has therefore been entirely wasted. 1

It is an object of my invention to provide for the conservation of this energy, in part at least, therebycutting down on the power required to keep the system in operation and'to -maintain the necessary pressure in the working chamber. -'This is accomplished by utilizingthe air under pressure which is released from the lock, either directly or indirectly, as a source of energy to aid maintain the required pressure in the system. In one form of my invention theair released from thelock is led directlyto the intake side of the main air compressor or to a booster, thereby enabling the compression unit employed to .op

,erate in'part at least upon air which is already partly compressed.

Itwisanother object of my invention to apply this saving of pressure to the'type of system n which, because of the size of the operation, may have a plurality of locks, particularly material locks, through the same bulkhead, and to provide for producing partial compression in one look by transferring into it the compressed air discharged upon decompression of another lock.

'Itis also an'object of my invention to provide improvements in the system and controls thereattained.

In'the drawings which represent certain preierr'ed embodiments of my invention and which form apart of the specification,

Figure 1 is a diagrammatic, vertical, longitudinal section illustrating a portion of a tunnel with we bulkhead therein confining a work chamber whi'ch' istto be maintained under pressure and with an air-lock'in the bulkhead'and' showing a diagrammatic representation'of an air compressor forto enable the foregoing results to be efilciently and its connections to the working chamber'and xi :-x g

inthe work of compressing the air necessary to' Figure 2 is a diagrammatic representation of 'my invention with modifications which make it applicable to a system of two locks in one bulkhead.

I Figure 3 is a diagrammatic representation showing another application to a two lock system;

The method heretofore pursued for moving men and/or materials through the bulkhead is substantially as follows: I i

To makethe transfer from the atmospheric w pressure ofth-e shaft or tunnelentrance II to the elevated pressure of the compression chamberl2 both doors to the air lock l3 are first closed and the pressure in the lock is reduced to atmospheric orto the pressure of the chamber I I.

The outer door 14 may then beopened and the men or materials introduced into the lock. The door 14 is" then closed, and air under pressure is introduced into the lock through pipe l5, controlled by valve l6, which may be operated from 6 within or without the look by means of hand controls Ila and 41b. When the pressure in the lock 13 equals the pressure in the chamber I2, the airtight door l8 maybe opened and the men or materials passed into the chamber l2.

To remove men or materials from the com-. pression chamber-the process is reversed. Doors I l and !8 are closed, pressure inthe lock is equalized with pressure in the compression chamber 12, the door I8 is opened, the men or materials to be decompressed are placed in the lock, the door I8 is closed, pressure is released through outlet 23, pipe 24, and valve I9 operable by means of hand controls 200, or Zilb from outside or inside the lock l3 until the pressure in the lock equals the pressure in the shaft or tunnel entrance II. The door Hi may thenbeopened and the decompressed men or materials removed.

A procedure of substantially this nature is necessary for each introduction or removal of men or materials into or from the compression chamber, and it is easily seen that each decompression which occurs results in an irrevocable loss of the pressure in the air look. This loss is wasteful and expensive, and the loss reflects itself in the increased work which the compressor must accomplish to maintain the pressure in the working chamber. It is tothe substantial elimination of this waste and expense that my inven The apparatus shown in Fig. 1 comprises a valve 2| operable by means of hand controls Hg, or 22b without or within the air lock which governs the flow of air through the outlet 23 and pipe 24.

The pipe leading from the valve 2! is connected to the intake port 26 of the compressor indicated generally at 21. At any suitable point on this pipe, preferably within the space H or elsewhere, open to the atmosphere, is situated an inwardly opening check valve 28.

Pressure gauges are situated on the outer side of either end of the air lock to indicate or'" record the pressure within the lock, and gauges 3| and 32 respectively indicate the pressure in, the compression chamber and in thelook to those inside the lock. Thus the pressure within the air lock may be read or recorded on either side of;

the bulkhead and within the lock.

The operation of the air lock on removing men or materials from the working chamber is as follows: H

Doors l4 and I8 are-shut; valve [6 is opened to equalize pressure in compression chamber l2 and airlock l3; door I8 is opened, men or materials placed in lock; door I8 is closed; valve I6 is closed; valve 2| is opened from within or without the air lock, whichever is convenient; the pressure in the lock forces the air from the lock into the pipe 25 leading to the intake port ,26 of the compressor 21 until the pressure in the air lock l3 equals the pressure in the space H, at which time the check valve 28 opens and the evacuation of the air lock 13 ceases; the door "is opened and the men or materials removed.

It will be noted that in each case the equalization of pressure between the lock I3 and the chamber I2 is accomplished by putting these two chambers in communication with each other. This pressure equalization may be accomplished in other ways, as for instance, by connecting the pipe 29- with the chamber I3, but however it is done, work is necessary to raise the pressure in the lock l3 to that of the chamber l2, and this work done is necessarily wasted when the pressure is released at valve IS in the-subsequent exhaustion of the lock l3 by now used methods.

However, if the apparatus of my invention is utilized in decompression, the air lock is connected to the intake of the compressor and the air under pressure transferred thereto, and the work and necessary energy to do the work of maintaining the pressure in the compression chamber l2v is thus reduced, as the necessity of bringing the air which fills the air lock after each opening thereof, from atmospheric pressure to maximum required pressure is, in part, obviated.

This results in a saving of power used=to drive the compressor and a consequent saving of cost of operating the system. i

It can be seen that if my invention is applied to a two stage compressor the air lock to be decompressed may first be put into communication with the second or high pressure stage of the come pressor until the pressure in the air lock is substantially reduced, and then a switch made to the low pressure stage of the compressor by means of valves or other known means.

It would also be feasible and, in large operations, possibly more economical, to install a small compressor or booster at the low pressure sideof the lock [3, to the intake port of which the pipe 25 could be connected, the outlet side of the compressor being connected to the compressionchamber I 2, and the small compressor would then effect the saving heretofore described by supplementing the work of the main compressor.

In Fig. 2 is shown an optional embodiment of my invention showing the use of a'small compressor or booster applied to a system of two locks. This embodiment is particularly applicable to large operations where substantial quantities of material are being passed through the bulkhead and results in a considerable saving in the total workdone in compression by utilizingthe pressure in one look partially to compress the air in the other and thus lessen the work done by the booster.

The locks 34:and 35 have air pipes 36 and 31 connected to three way valves 38 and 39 operable by, means of hand levers 40 and 4| or in other convenient manner. By proper setting of valves 38 and 39 air connection between the lock to be decompressed may be established, through pipe 43, with the lock in which the pressure is to be raised. The pipe 43 is also in communication with the inlet side of the booster 42 through pipe 45. Situated on the low pressure side of the bulkhead and connected to the pipe 45 is a check valve 48 which operates to admit air-when the pressure in the pipe 45 equals or falls below the pressure on the low pressure side of the bulkhead.

.The locks 34 and 35 are-also adapted to be putv in communication with the outlet side of the booster through pipe 44, by setting valves 38 and 39.

This double lock system may preferably be used by alternating the locks, and when so used, the operation is as follows: 1

Valves '38 and 39 are adjusted to put the locks in communication through pipe 43, until the pressure in the two locks is equalized. Lock 35 is then connected to the pipe 44 by proper setting of the valve 39 and lock 34 is left in communication with pipe 43. The booster now acts to decompress lock 34 and compress lock 35. the pressure in 34 equals that on the low pressure side of the bulkhead; the check valve 46 will act to prevent any further evacuation and the door.

on the low pressure side of the bulkhead may be opened. At substantially the same time the air in the lock 35 will have been compressed to a point where the door on the high pressure side of the bulkhead may be opened. Materials may now be introduced into or removed from the locks simultaneously from both sides of the bulkhead. When this is completed, the doors respectively on the inside and outside of the bulkhead may be The saving in power is thus shown toresult from two distinct applications of pressure form-,

erly wasted by venting, i. e part of the pressure in one lock is used to compress the air in another lock, and after pressure equalization has been reached, the remainder of compressed air in the lock being decompressed is utilized to lessen the load on the booster.

Fig. 3 shows another embodimentas applied toa system having a plurality of locks in whichthe equalization of the pressure in the locks is accomplished through the booster. A single four way valve 41 is shown, capable of putting one lock in Whenv contact with the intake of the booster and the other with the outlet thereof. A check valve 48 is provided in connection withthe intake line to the compressor which will operate if the air leaving one lock is not suificient for the needs of the other.

The specific types of valves or connections used in these two last mentioned embodiments of this invention are not shown, nor need they be, since the various detailed means for achieving the objects of the invention will be obvious. The use of three or four way valves as described is optional, the type of valve or connection being subordinate to the purpose accomplished.

Where relatively high pressures are used and decompression is accomplished in stages by use of a series of two or more systems of air locks through bulkheads situated at relatively large distances from each other in the tunnel, my invention is peculiarly applicable both to man and material locks. Decompression would thus be carried on from maximum pressure to an intermediate pressure at the first bulkhead and from intermediate to atmospheric at the second.

The present apparatus may be used in connection with locks for the passage of men or materials or both. It is especially applicable to use in connection with locks for passing materials as these are usually of large volume and the air pressure is released from them at a rapid rate as compared with the rate at which the air is released from man looks.

While I have illustrated and described in detail certain preferred forms of my invention, it is to be understood that changes may be made therein and the invention embodied in other structures. I do not, therefore, desire to limit myself to the specific construction illustrated, but intend to cover my invention broadly in whatever form its principle may be utilized.

I claim:

1. In an apparatus for conducting operations under pressure, a compression chamber, an air lock for passage of men or materials into or out of said compression chamber, a compressor, duct means for conducting air under pressure discharged from the lock to the intake of the compressor, and duct means for conducting compressed air from the outlet of the compressor to the compression chamber whereby the energy of the compressed air evacuated from the air lock assists in maintaining the pressure in the compression chamber.

2. In a pressure excavation apparatus, a bulkhead, a compression chamber, an air look through the bulkhead, a compressor, means for connecting the air lock with the intake of the compressor, valve means connected with the low pressure side of the bulkhead and with the compressor to prevent evacuation of the air look below the pressure of the low pressure side of the bulkhead, and means for utilizing the energy of the compressed air evacuated from the air lock to assist in maintaining pressure in the compression chamber.

3. In an apparatus for conducting operations 5 under pressure, a compression chamber, a compressor, a plurality of air locks for passage of men or material into or out of said compression chamber, air connections between the air locks, air connection between the air locks and the intake of 10 the compressor, air connections between the air locks and the outlet of the compressor, and means for opening'and shutting these connections so that pressure in one look may be utilized to raise pressure in another lock. 15

4. An apparatus as claimed in claim 3 in which a check valve is in connection with the air connection to the inlet side of the compressor adapted to operate to prevent the evacuation of any look below a stated terminal pressure.

5. An apparatus as claimed in claim 3 in which three way valves are located on the various air connections, adapted to put the locks in communication with each other or with either intake or outlet sides of the compressor.

6. An apparatus as claimed in claim 3 in which the connection between locks is made through the compressor, and valve means for opening and closing the connection between the locks and the, connection between any lock and either side of 1 80 the compressor.

7. In apparatus for conducting operations under pressure a compression chamber, a compressor, duct connections between said compressor and said compression chamber, a plurality of 35 looks communicating with said compression chamber, valve controlled duct connections between the locks to permit exhaustion of a look under high pressure to a look under lower pressure until the pressure between the two is sub- 40 stantially equalized, valve controlled duct connections between each lock and the inlet of the compressor to permit a lock to be exhausted to a pressure below said equalization pressure, and valve controlled duct connections between the looks and the compression chamber to permit the pressure in a lock to be raised above said equalization pressure. 5

8. In an apparatus for conducting operations under pressure, a compression chamber, a plurality of air locks for passage of men or material into or out of said compression chamber, a source of air pressure, valve controlled duct connections from the source of air pressure whereby compression may be applied to the compression chamber and locks, and valve controlled duct connections between the locks whereby the pressure in one look may be utilize-d to raise pressure in another lock. 7

WILLIAM B. UPDEGRAFF. 

